Exhalation valve



All@ 22, 1950 H. L. BURNS ET A1. 2,519,349

EXHALATION VALVE Filed Oct. 8, 1945 Patented Aug. 22, 1950 UNITED STATES PATENT OFFICE EXHALATION VALVE Henry L. Burns and Verner J. Wulff, Yellow Springs, Ohio (Granted under the act of March 3, 1883, as amended April 30, 1928; 3710 0. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to us of any royalty thereon.

This invention relates to a new and improved exhalation valve.

A primary object of the invention is to provide an exhalation valve for oxygen masks and the like that will permit exhaust gases to escape from the'mask only after a predetermined pressure has been attained within the mask. In the present type of oxygen masks in commonuse for pressure breathing, an exhalation valve is provided which is subjected to load pressure of the incoming gas on one side with an additional spring pressure applied thereto and to pressure within the mask on the opposing side which will permit the exhaust valve to open and release the exhaust gas within the mask only when the pressure within the mask overcomes the pressure exerted by the load of the incoming gas and spring. In the event of a leakage of the conventional check valve 'controlling the flow of gas into the facepiece of the mask or in the event of failure of the pressure regulator at the source of oxygen supply to regulate the pressure of gas owing into the mask, the pressure against both sides of the valve is equalized and the valve is rendered inoperative forcing the user to remove the mask in order to exhale. tion to provide an exhalation valve that will function at all times to permit the user to exhale upon attaining a predetermined pressure within the mask.

Another object of the invention is to provide an exhalation valve .that will permit the user to exhale at a predetermined pressure within the mask where the ow of oxygen is not regulated as with an oxygen bottle commonly used when performing parachute jumps from high altitudes.

Other and further objects and advantages of the present invention will be apparent to those skilled in the art from a consideration of the following description of a specic embodiment of the invention shown in the accompanying drawings in which:

Fig. 1 is an elevational sectional View of the facepiece of the conventional mask showing the exhalation valve mounted therein.

Fig. 2 is an elevational sectional view of the valve assembly and Fig. 3 is an elevational plan view with the housing broken away showing the valve in closed position.

Referring now more specically to the draw- It is an object of the invenu seat 6.

vvalve 'I and loading diaphragm I2.

ing, the numeral I designates the facepiece of the conventional oxygen mask having the passageway 2 and the check valves 3, 3 therein.

The valve assembly 4 is mounted in said mask in the conventional manner, said valve assembly having the rigid housing 5 and the port 6 in the upper end of said housing. The internal Wall of said port 6v extends downwardly into said casing and the lower end of said wall forming a valve Mounted Within said housing 5 is the valve 'I having the exhaust diaphragm 8 constructed of rubber or similar material mounted thereon by means of the bolt 9 and nut III. The exhaust diaphragm 8 has the annular bead II adjacent the outer edge thereof to permit the movement of said diaphragm. The loading diaphragm I2 is mounted in the lower end of the housing, and is constructed to provide an effective load area of less circumference and consequently less load capacity than the port 5, the annular outwardly ared ring I2 anchoring said exhaust diaphragm and loading diaphragm within the housing. The loading diaphragm I2 has the annular bead I3 adjacent the outer edge thereof to permit the movement of said diaphragm. Mounted on the loading diaphragm I2 is the spring retainer I4 in which the spring I5 is seated, exerting opposing pressure against the The lower end of the casing 5 has the downwardly extending tubular passageway I6, the internal walls thereof being ared providing the internal annular shoulder I8. Mounted on said annular shoulder I8 is the coil spring I9, the upper end of said spring I9 exerting pressure on the loading diaphragm I2. The housing 5 has the outlet port 20 through which exhaust gas escapes whenthe valve 1 is in open position. rIhe port 2I in the housing 5 and the port 22 in the annular ring I2 permits the equalization of barometric pressure between the exhaust and loading diaphragms and the atmosphere.

In operation, the pressure flow of oxygen to vthe mask is predetermined and controlled by reg.-

ulators at the source of supply. The oxygen flows into the mask through passageway 2 and through check valves 3, 3 into the inside of the facepiece of the mask. The pressure of gas in the passageway 2 is transmitted to the diaphragm I2 through the passageway I6, forcing the diaphragm I2 upwardly against the valve 'I, moving same into closed position with valve seat 6. Upon pressure being built up in the mask by the oW of gas through the check valves 3, 3 and by the exhalation of the wearer, said pressure will act upon the valve 1. The circumference or the cross-sectional area and the consequent load capacity of the port 6 in conjunction with the effective area of diaphragm 8 being greater than that of the effective area of the diaphragm' I2, only `suiiicient additional pressure over that -ofthe loading diaphragm' I2 is required to overcome the resistance of the spring I9 to permit the valve 'l to move downwardly out of engagement with the valve seat 6' and permit pressure in the mask to be relieved by the eX- haust gas flowing through port 20. Immediately upon reduction of the pressure within the-"mask, the spring I9 and the pressure of t-he incoming gas against the diaphragm I2 will close'the valve 1 maintaining the predetermined i'pressure in the mask until by exhalation of the wearer the pressure is again builtup'to'alpoint 'where the valve 'l will again open. The pressure' differential required to operate the exhaust diaphragm is graduated,4 becoming lessl'asthe pressure 4ofincoming gas increases, until a pointis reached wherethe pressure required toifoperate theexhaust diaphragm is equal 'tothat of `the 'incoming'gas, at whichfpoint theexhaust valve, because f the 'greater pressure effective area, lwill :depressthe spring IB'and remain @eng-allowing the gas'in the facepieceofthe mask'to escape throughtheport'Z until the gas pressure in the facepiece-of the mask is' reduced below the point ofequalization,'at which time' the normal operation of the assembly asheretofore describdis "resumed,

No claim of invention is made' tov theconstruction" herein described except the feature: `f'pror viding-an exhaust-lportof greater load capacity 'thanithe' loading means, permitting the `exhaust valve to open' under any circumstances, upon 'reaching a Apredetermined maximum 'ipressu're rwithin the facepiece'of thev mask.

4Having V-thus 'described' ourl invention, whatfwe claim is new and desire 'tolsecure by 'Letters -Patent of-the` United States is:

1. An exhalation valve assembly comprising, vfa housing'adapte'd to'bemounted in the facepieoeof a pressure breathing mask, an inlet port andan outlet port inlsaid housing, a'valve' insaidhousing controllingthe Vviiuid"iiow'through the 'inlet and 'outlet ports, aV pressure 'responsive'mea'ns in said housing subjected to inlet'and outiet pres- "sures operatively connected tosaid valve' for operation thereoLa load'pressure responsive means in saidY housing having a` lesser working 'pressure V'area than said 'nrst mentioned pressure responsive means, resilient means positioned between said iirst' mentioned pressure responsive means and said' load pressure responsive means and resilient means positioned between saidload pressure responsive ymeansan'd the housing wall toresiliently hold said' valve and both pressure "responsive 'meansl ina predetermined related `position,:and a passageway in said housing to permit .the applicationof fluid under pressure tosaid load .pressure responsive meansifor closing said valve whereby pressure of fluid in said inlet port equal to or greater than the pressure of fluid on said load pressure responsive means eiects valve opening.

2. An exhalation valve assembly having a valve housing, a valve in said housing, an exhaust diaphragm mounted'on said valve, a load ldiaphragm in said housing, an annular retainer ring anchoring said diaphragms within the housing, means Abetween said diaphragms holding same in posi- 'tion,ra load pressure inlet port in said housing,

means mounted in said port for exerting mechanicalv pressure against said load diaphragm, an ex- 'ha'lation port in said housing of greater load ca- `pacitylthan .the pressure area of the load diaphragm, the lower end of said exhalation port forming a valve seat for said valve.

3. Ina valve'assembly, a housing, an inlet port and anvfoutlet. portin said housing, a valve controlling said ports, an exhaust diaphragm and a load diaphragm actuatingsaidvvalve, a spring-retainer mounted on. said load diaphragm, aicoil spring'seated in saidspring retainer, said spring actingV against said exhaust diaphragm and said load diaphragm, a tubular passageway in said housing topermit the application of uid Ipressure tosaid load diaphragm, a spring mounted in said tubular passageway exerting pressure against said load diaphragm, said exhaust diaphragm having a greaterpressure leieetive area than said load diaphragm.

4. In an exhalation Valve assembly of the character describedf a housing, an inletport andan outlet-port in said housing, a-valve `in said housing, anexhaust diaphragm and aloaddiaphragm actuating said valve, said exhaust diaphragm having agreater pressure effective area than the-said loadl diaphragm, means for applying constant id pressure to said load diaphragm to hold the valve in-closed position,.said inlet port having a crosssectional area ofproper sizelfor. admitting sumcient uid pressure to said exhaust diaphragm lto overcome said pressure upon .said load .dia-

phragm.

vHENRY L.` BURNS.

VERNER-J. WULFF.

REFERENCES CITED The following references 1are of recordinY the Yfile of this patent:

vNumber Name Date 42,430 Boyle Apr .19,.1864 i 1,454,353 'Thrush May"`8, 1923 1,846,483 Gilbert. Feb. 23,1932 2,384,669 Fields Sept. 11,1945 2,387,123 Deming Oct/.16, 1945 -FOREIGN PATENTS Number VCountry Date `322,993 Great Britain -'June 11, 1929 -784 188 France Apr. 23,"1935 

